Not long after the advent of the personal computer, input devices were developed to supplement or replace the traditional keyboard. Such devices include mice, trackballs, light pens, tablets with styli, joysticks, and capacitive, touch-sensitive screens. While such devices are now commonplace and inexpensive for personal computers with relatively small screens, an analogous means of interaction for large screen video displays has not yet been developed. Indeed, given the limitations of most large screen technologies, the need for interaction has not previously arisen since most of these prior displays were not viewable in a proximity close enough to warrant interactively with the viewer(s).
The large screen display (LSD) industry is today dominated by light emitting diode (LED) and field emission display (FED) technologies which are limited by a minimum viewing distance of at least several meters. Obviously, it is impossible, at that distance, to physically interact with a display. Moreover, because LED and FED displays can only be viewed from distances greater than several meters, the problem does not exist.
However, there is a need in the marketplace for LSD""s that are both proximally viewable and possess interactive capabilities. Moreover, such displays must be rugged, have a wide operating temperature range, and be visible in high ambient light. Such video displays would be useful in airports, terminals, amusement parks, simulators, museums, trade shows, exhibits, and the like. With the proliferation of handheld and notebook computers, additional opportunities exist for LSDs to interactxe2x80x94not only with viewers, but also with the viewers"" personal computing devices.
U.S. Pat. No. 5,455,882 discloses an interactive, thin, optically-based apparatus which is designed for interaction with a remote control device such as an infrared remote control unit. This display is comprised of laminar waveguides that are driven by one or more lasers, modulated by a video signal, that scan each waveguide. The display is not modular in nature, and the nature of the interactive capabilities is not relevant for large screen applications. Scanning and light detection are done remotely on a separate substrate from the display waveguides. This invention does not describe a software component that controls the visual feedback on the display in response to the nature (e.g., duration or position) of the interactive initiative.
U.S. Pat. No. 5,127,078 discloses an apparatus for the simultaneous viewing and receiving of images, transferred through a system of interconnected fiber optic faceplates. The sending and receiving fibers are integrated and unnoticeable, and the device is designed to simultaneously display and view images. Because of this, it uses a high density of very tightly packed small diameter fibers. This has several undesirable effects for inexpensive outdoor displays, namely high cost, low contrast, and increased weight. Moreover, the display is used in 1:1 configuration such that no enlargement is made of the input image.
U.S. Pat. No. 5,953,469 discloses an optical display comprised of a matrix of optical waveguides and mechanical light switches. Like fiber optic displays, this invention possesses intrinsic interactive capabilities. However, because the apparatus is constructed from sandwiched layers of glass (or plastic) and various conductive and dielectric layers, the invention is not well suited to the demands of being placed in direct pedestrian contact, not is it suited to great thermal extremes. Since the light switches are operated electrostatically, the display is susceptible to shock. Also, the efficient operation of the display requires that it be hermetically sealed, indicating that it is not a particularly robust technology. Lastly, the device is driven, most efficiently, from LEDs. Because of the manner in which the LEDs are coupled to the waveguides, sufficient luminous flux levels for high ambient lighting conditions cannot be currently achieved.
The invention here disclosed is a novel solution to many of the limitations of the prior art. A preferred embodiment of the invention includes a modular electro-optic video display assembled from inexpensive, plastic tiles. The tiles may employ fiber optics or solid plastic lightguides to convey images from a first, or projection surface, to a second, or display surface where the image is enlarged. A description of such an apparatus has been disclosed in U.S. patent application Ser. No. 09/569,811, now allowed, and U.S. patent application Ser. No. 09/482,290, now U.S. Pat. No. 6,304,703.
In the preferred embodiment of the present invention, each display tile is populated with additional optical fibers or lightguides which are collected into a third, or input, surface for the purpose of detecting electromagnetic radiation, preferably in the 200-1300 nm band, which corresponds to UV, visible, and infrared light. This light collection and detection provides a means of interaction with the display, whether personally or through handheld computing devices or cellular (xe2x80x9cwirelessxe2x80x9d) telephones. Preferably, the light detection circuitry is coupled to the same computer that drives the display, thereby constituting a feedback loop. Because the preferred display tiles are made from thermoplastic and composite materials, they are durable and able to withstand the abuses of an interactive environment. Unlike CRT-based touch sensitive screens, which employ a capacitive film, a preferred embodiment of the present invention employs an optically-coupled, computer-controlled sensor array which senses not only position, but also movement (velocity), attack (acceleration), patterns, and timing.